| The valorization of non-submersible marine sediments of the Grand Port Maritime de Dunkerque GPMD as a new aggregate presents alternative solutions in the field of civil engineering for a better management. The work of this thesis focus on the valorization study of marine sediment in road engineering (laboratory and in situ) and the study of the durability of concrete blocks made with marine sediment for the protection of harbour structures.;The first part of valorization non-submeresible sediments in road engineering is divided into three steps:;The first step was devoted to the physical, mechanical and mineralogical characteristics of these materials, as well as their chemical composition and environmental effects, in an attempt to characterize their behavior and their potential as material in road engineering. The second step presents an experimental methodology for the development of a road foundation made from dredged fine sediment, dredged sand, lime and hydraulic binder. The last step describes the construction of an experimental road and analyses the mechanical properties of cores drilled from the road and the results of deflection tests. An environmental assessment, based on leaching tests, was also performed.;The second part of the thesis focuses on a durability study of two concrete blocks with two different percentages of sediment. This part is divided into three steps:;In the first step, mechanical, physical and chemical characteristics of two types of concrete containing12,5% and 20% of dredged marine sediments are presented and discussed. In the second step, we have examined the durability of these types of concrete with regards to alkali-aggregate reaction, sulphate attack and freezing and thawing cycles. The results of this study will serve in order to better understand the impact of the incorporation of sediments into the concrete (percentage of incorporation, porosity...) and the effect on the mechanical resistance and the degradation mechanisms.;This study is the framework of collaborative research work between Mines de Douai and the University of Sherbrooke (Canada) with the support GPMD and the Region.;Keywords: Dredged sediments, Valorisation, environmental assessment, experimental road construction, mechanical performance, durability of concrete made from marine sediment, destructive and non destructive testing. |
